A greyed out iCloud Backup banner is a known Apple-related issue.
Please follow these suggestions to resolve this issue, checking between each step to see if iCloud backups are enabled.
- Go to Settings > iCloud. Tap the Apple ID and sign out of iCloud with your Apple ID password. Wait 20-30 seconds and sign back IN.
- Make sure that your iDevice is connected to WiFi. WiFi is required for iCloud backups to initiate.
- Check that airplane mode is OFF (Settings > Airplane Mode). (Remember, you must have a WiFi connection to start your backup!)
- If “Restrictions” are enabled in Settings > General / Screen Time > Restrictions / Content & Privacy Restrictions; scroll down to 'Allow Changes' and set Account / Account Changes to "Allow"
- Reset the network settings (Settings > General > Reset > Reset Network Settings)
- Update your iOS device to latest version of iOS
- Verify you have enough memory left on your iDevice. Tap Settings > General > About > Available and make sure that you have at least 50MB’s available.
If you continue to have issues, please check the Apple System Support page for any live iCloud issues, and - if needed - contact Apple Support for additional assistance!